//
//  list.c
//  Algorithm
//
//  Created by ViliWen on 1/18/16.
//  Copyright © 2016 wlf92. All rights reserved.
//

#include <stdlib.h>
#include <string.h>

#include "list.h"

void list_init(List *list, void (destroy)(void *data))
{
    list->size = 0;
    list->destroy = destroy;
    list->head = NULL;
    list->tail = NULL;
    return;
}

void list_destroy(List *list)
{
    void *data;
    while (list_size(list) > 0) {
        if (list_rem_next(list, NULL, (void**)&data) == 0 && list->destroy != NULL) {
            list->destroy(data);
        }
    }
    
    memset(list, 0, sizeof(list));
    return;
}

int list_ins_next(List *list, ListElmt *element, const void *data)
{
    ListElmt *new_element;
    if ((new_element = (ListElmt*)malloc(sizeof(ListElmt))) == NULL) {
        return -1;
    }
    
    new_element->data = (void*)data;
    if (element == NULL) {
        if (list_size(list) == 0) {
            list->tail = new_element;
        }
        new_element->next = list->head;
        list->head = new_element;
    }else{
        if (element->next == NULL) {
            list->tail = new_element;
        }
        new_element->next = element->next;
        element->next = new_element;
    }
    list->size++;
    return 0;
}


int list_rem_next(List *list, ListElmt *element, void **data)
{
    ListElmt *old_element;
    if (list_size(list) == 0) {
        return -1;
    }
    if (element == NULL) {
        *data = list->head->data;
        old_element = list->head;
        list->head = list->head->next;
        if (list_size(list) == 1) {
            list->tail = NULL;
        }
    }else{
        if (element->next == NULL) {
            return -1;
        }
        *data = element->next->data;
        old_element = element->next;
        element->next = element->next->next;
        if (element->next == NULL) {
            list->tail = element;
        }
    }
    free(old_element);
    list->size--;
    return 0;
}


//
//#define list_size(list) ((list)->size)
//#define list_head(list) ((list)->head)
//#define list_tail(list) ((list)->tail)
//#define list_is_head(list, element) ((element) == (list)->head?1:0)
//#define list_is_tail(list, element) ((element)->next == (list)->tail?1:0)
//#define list_data(element) ((element)->data)
//#define list_next(element) ((element)->next)
